Compressive strength of clay-based geopolymers: A concise review of the influencing factors and underlying mechanisms

Geopolymer is a green inorganic polymer that is produced by using aluminosilicate materials, such as clay materials and industrial by-products in a highly alkaline environment. In recent years, clay had been widely used in the manufacturing of ceramics and building construction. The use of clay in geopolymer production not only reduces the environmental impact of traditional cement production, but also provides a sustainable alternative for various construction applications. Its versatility and cost-effectiveness make it an attractive option for industries looking to reduce their carbon footprint. This review is mainly focused on factors that influence the strength of clay-based geopolymers. Several factors, such as clay type, alkaline activator solution, aggregates, system ratio, curing temperature and time were discussed. The review also included mechanism of geopolymerization reaction. Overall, a combination of the appropriate clay type, aggregates, curing conditions, and activator solution is essential in achieving a high strength in geopolymers. Additionally, emerging reinforcement strategies such as nanomaterials, hybrid binders and fiber reinforcements are also discussed in context of mechanical behaviour of clay-based geopolymer.